Gene Expression Analysis of Transgenic Myc-Driven Liver Tumor Formation and Regression
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ABSTRACT: Gene expression changes were examined in transgenic MYC-driven liver cancers at different time points as tumors formed and upon early regression. Time points evaluated include: Control (non-tumor bearing), Pre-tumor (mice were removed from doxyclycine in their diet to induce MYC oncogene expression for 4-5 weeks), Tumor (tumor nodules from mice that had been off of doxycycline for 8-9 weeks) and Early tumor regression (tumor-bearing mice were placed back on doxycycline for 72 hrs to inhibit MYC oncogene expresion). MYC-Driven Mouse Tumor Models are described in Schahaf, et al., Nature, 2004 and Goga, et al., Nature Medicine, 2007.
Project description:Gene expression changes were examined in transgenic MYC-driven liver cancers at different time points as tumors formed and upon early regression. Time points evaluated include: Control (non-tumor bearing), Pre-tumor (mice were removed from doxyclycine in their diet to induce MYC oncogene expression for 4-5 weeks), Tumor (tumor nodules from mice that had been off of doxycycline for 8-9 weeks) and Early tumor regression (tumor-bearing mice were placed back on doxycycline for 72 hrs to inhibit MYC oncogene expresion). MYC-Driven Mouse Tumor Models are described in Schahaf, et al., Nature, 2004 and Goga, et al., Nature Medicine, 2007. 11 Total Samples: 3 Control, 4 Pre-Tumor, 4 Tumor, 4 Early Tumor Regression. Control = LAP-tTA transgenic mice. Others = TRE-MYC x LAP-tTA double transgenic mice (doxy off).
Project description:After 8 days of OKSM induction via doxycycline, Nanog-Neo secondary MEFs (Wernig et al. Nature Biotechnology 2008) were FACS sorted by KLF4, Oct4, and EpCAM expression. Four major subsets of MEFs have been sorted and analysed for gene expression.
Project description:The suppression of oncogenic levels of MYC is sufficient to induce sustained tumor regression associated with proliferative arrest, differentiation, cellular senescence and/or apoptosis, a phenomenon known as oncogene addiction. However, after prolonged inactivation of MYC in a conditional transgenic mouse model of Em-tTA/tetO-MYC T-acute lymphomablastic lymphoma (T-ALL), some of the tumors recur, recapitulating what is frequently observed in human tumors in response to targeted therapies. Here we report that these recurring lymphomas express high levels of either transgenic or endogenous Myc suggesting that tumors continue to be addicted to oncogenic levels of MYC. Many of the recurring lymphomas (76%) harbored mutations in the tetracycline transactivator (tTA) resulting in expression of the MYC transgene even in the presence of doxycycline. Many of the remaining recurring tumors expressed high levels of endogenous Myc which was in some cases associated with a genomic rearrangement of the endogenous Myc locus or overexpression of Notch1. Gene expression profiling confirmed that the primary and recurring tumors have highly similar transcriptomes. Importantly, shRNA-mediated suppression of the high levels of MYC in recurring tumors elicited both suppression of proliferation and increased apoptosis confirming that these tumors remain oncogene addicted. These results suggest that tumors caused by MYC overexpression remain addicted to high levels of expression of this oncogene. 13 samples, no replicates included
Project description:Transgenic MYC/Twist1 HCC uncergoes tumor regression with persistence of minimal residaul disease (MRD) in the liver upon oncogene deprivation.
Project description:This experiment investigates the expression characteristics of residual breast cancer cells. Primary mammary epithelial cells taken from female mice with doxycycline-inducible hMyc- and Neu/Her2-oncogenes were grown in 3D organoid cultures. Upon the addition of doxycycline (200ng/mL) to the medium the expression of the oncogenes gets activated and the cells start uncontrolled proliferation resembling tumor growth. Tumor samples were taken after 5 days of oncogene induction. Subsequently, doxycycline was removed from the medium, which silences oncogene expression and results in rapid tumor regression. Residual samples reminiscent to the non-induced (normal) structures were taken after 7 days of de-induction (12 days overall). Non-induced structures were grown and sampled in parallel.
Project description:Lymphomagenesis was induced by conditional expression of transgenic c-Myc oncogene. Profile of genes expressed in tumor cells was compared with profile of genes in the same cell line treated for 12 hours with doxycycline to abrogate expression of transgenic c-Myc. Six different tumor cell lines were tested.
Project description:This experiment investigates the genome wide DNA methylation landscape of residual breast cancer cells. Primary mammary epithelial cells taken from female mice with doxycycline-inducible hMyc- and Neu/Her2-oncogenes were grown in 3D organoid cultures. Upon the addition of doxycycline (200ng/mL) to the medium the expression of the oncogenes gets activated and the cells start uncontrolled proliferation resembling tumor growth. Tumor samples were taken after 5 days of oncogene induction. Subsequently, doxycycline was removed from the medium, which silences oncogene expression and results in rapid tumor regression. Residual samples reminiscent to the non-induced (normal) structures were taken after 7 days of de-induction (12 days overall). Non-induced structures were grown and sampled in parallel to the residual structures.
Project description:The neural behavior of glioblastoma, including the formation of tumor microtubes and synaptic circuitry, is increasingly understood to be pivotal for disease manifestation (Osswald et al. 2015; Venkatesh et al. 2015; Weil et al. 2017; Venkataramani et al. 2019; Venkatesh et al. 2019; Alcantara Llaguno et al. 2019; Venkataramani et al. 2022). Nonetheless, the few approved treatments for glioblastoma target its oncological nature, while its neural vulnerabilities remain incompletely mapped and clinically unexploited. Here, we systematically survey the neural molecular dependencies and cellular heterogeneity across 27 glioblastoma patients and diverse model systems. In patient tumor samples taken directly after surgery, we identify a spectrum of neural stem cell morphologies indicative of poor prognosis, and discover a set of repurposable neuroactive drugs with unexpected and consistent anti-glioma efficacy. Glioblastoma cells exhibit functional dependencies on highly expressed drug targets including neurological ion channels and receptors, while interpretable molecular machine learning reveals downstream convergence on secondary drug targets (COSTAR) involving AP-1-driven tumor suppression. COSTAR enables in silico drug screening on >1 million compounds that are validated with high accuracy. Multi-omic profiling of drug-treated glioblastoma cells confirms rapid Ca2+-driven AP-1 pathway induction to represent a tumor-intrinsic vulnerability at the intersection of oncogenesis and neural activity-dependent signaling. Finally, the consistent anti-glioma activity across patients and model systems is epitomized by the antidepressant Vortioxetine, which synergizes in vivo with approved glioblastoma chemotherapies. In all, our global analysis reveals that the neural vulnerabilities of glioblastoma converge on an AP-1 mediated gene regulatory network with direct translatable potential.